Energy coupling to ATP synthesis by the proton-translocating ATPase

1982 ◽  
Vol 67 (1) ◽  
pp. 1-12 ◽  
Author(s):  
Peter C. Maloney
Keyword(s):  
Atp Synthesis ◽  
Energy Coupling ◽  
Proton Translocating Atpase

scholarly journals Effect of Tentoxin on the Activation and on the Catalytic Reaction of Reconstituted H+-ATPase from Chloroplasts

1992 ◽  
Vol 47 (3-4) ◽  
pp. 239-244 ◽  
Author(s):  
Petra Fromme Max-Volmer ◽  
Ingo Dahse Friedrich-Schiller ◽  
Peter Gräber
Keyword(s):  
Energy Transfer ◽  
Catalytic Reaction ◽  
Atp Hydrolysis ◽  
Atp Synthesis ◽  
Nucleotide Release ◽  
Transfer Inhibitor ◽  
Proton Translocating Atpase

Abstract The proton-translocating ATPase from chloroplasts, CF0F1, was isolated, purified and reconstituted into asolectin liposomes. The effect of the energy transfer inhibitor, tentoxin, on different functions of the enzyme was investigated. Tentoxin does not inhibit the nucleotide release during energization by a pH /ΔΨ jump, i.e. the activation of the enzyme is not influenced. ATP synthesis driven by a pH /ΔΨ jump and multi-site ATP hydrolysis are completely inhibited by tentoxin, whereas uni-site ATP hydrolysis is not influenced.

Molecular Features of Energy Coupling in the F0F1 ATP Synthase

Physiology ◽  
1999 ◽  
Vol 14 (1) ◽  
pp. 40-46
Author(s):  
Robert K. Nakamoto
Keyword(s):  
Atp Synthase ◽  
Catalytic Domain ◽  
Atp Synthesis ◽  
Energy Coupling ◽  
F0f1 Atp Synthase ◽  
Molecular Features ◽  
Rotary Mechanism ◽  
Transport Domain

H+ translocation is coupled to ATP synthesis in the F0F1 ATP synthase via a rotary mechanism. Catalytic turnover, site-site cooperativity, and H+ transport obligatorily involve rotation of a set of subunits. The transport domain in the membranous F0 and the catalytic domain in the F1 are mechanisms designed for generating torque.

scholarly journals A critical appraisal of evidence for localized energy coupling. Kinetic studies on liposomes containing bacteriorhodopsin and ATP synthase

1985 ◽  
Vol 230 (2) ◽  
pp. 543-549 ◽  
Author(s):  
R L Van der Bend ◽  
J Petersen ◽  
J A Berden ◽  
K Van Dam ◽  
H V Westerhoff
Keyword(s):  
Electron Transfer ◽  
Atp Synthase ◽  
Critical Appraisal ◽  
Atp Synthesis ◽  
Kinetic Studies ◽  
Energy Coupling ◽  
Proton Pumps ◽  
Specific Interactions ◽  
Mitochondrial Atp Synthase ◽  
Different Levels

In intact systems (chloroplasts, mitochondria and bacteria) many experiments have been reported which are indicative of localized coupling between ATP synthase and electron transfer complexes. We have carried out similar experiments with a system in which we may assume that specific interactions between the proton pumps are absent: reconstituted vesicles containing bacteriorhodopsin and yeast mitochondrial ATP synthase. The only experiment that gives results which differ from those previously published for intact systems concerns the effect of uncouplers on the rate of ATP synthesis at different levels of inhibition of the ATP synthase. We propose that this type of experiment may discriminate between localized and delocalized coupling.

Active urea transport in toad skin is coupled to H+ gradients

1989 ◽  
Vol 256 (5) ◽  
pp. F830-F835 ◽  
Author(s):  
J. Rapoport ◽  
C. Chaimovitz ◽  
R. M. Hays
Keyword(s):  
Active Transport ◽  
Energy Coupling ◽  
Disulfonic Acid ◽  
Urea Transport ◽  
Toad Skin ◽  
Carbonyl Cyanide ◽  
Disulfonic Stilbene ◽  
Active Transport System ◽  
Saline Solutions ◽  
Proton Translocating Atpase

Active transport of urea exists inwardly through the skin of the toad Bufo viridis and is enhanced by adapting the toads to hypertonic saline solutions. In this paper, we report our studies on the energy coupling of this active transport system. We have shown previously that this system is independent of sodium transport. We thus studied the possibility of coupling to proton transport by studying the following: 1) the effect of acidifying the epithelium by means of CO2 and protonophores, 2) the effect of alkalinizing the epithelium with the anion-exchange inhibitor 4,4'-diisothiocyanatostilbene-2,2'-disulfonic acid (DIDS) and by removal of chloride from the serosal medium, 3) the effect of inhibiting the proton-translocating ATPase of the skin, 4) dependence on mucosal pH. We found that 1) acidification of the epithelium by means of 5% CO2 and the protonophores carbonyl cyanide m-chlorophenylhydrazone (CCCP) and nigericin inhibited urea influx; 2) alkalinization of the epithelium by means of the disulfonic stilbene DIDS and by removal of serosal chloride increased urea influx; 3) inhibition of the proton-translocating ATPase of the skin by means of 1,3-dicyclohexylcarbodiimide (DCCD), N-ethylmaleimide (NEM), and sodium orthovanadate inhibited urea transport; 4) urea influx was unaffected by alkalinizing the external medium to 8.5 or by acidifying to 6.5; it was significantly suppressed by a mucosal pH of 5.5.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Photosensitive phosphoproteins in Halobacteria: regulatory coupling of transmembrane proton flux and protein dephosphorylation.

1981 ◽  
Vol 91 (3) ◽  
pp. 895-900 ◽  
Author(s):  
E N Spudich ◽  
J L Spudich
Keyword(s):  
Protein Phosphorylation ◽  
Action Spectrum ◽  
Atp Synthesis ◽  
Energy Coupling ◽  
Proton Flux ◽  
Protonmotive Force ◽  
Proton Efflux ◽  
Ph Gradients ◽  
Protein Dephosphorylation ◽  
Reversible Protein Phosphorylation

A photoregulated reversible protein phosphorylation system controlled by the halobacterial rhodopsins was recently reported. The results presented in this paper identify the initial steps in the pathway from the absorption of light to the photoregulated protein phosphorylation and dephosphorylation reactions. Action spectrum, biochemical, and genetic analyses show that the proton pump bacteriorhodopsin mediates light-induced dephosphorylation of three photoregulated phosphoproteins. Light absorbed by bacteriorhodopsin is used to establish a proton efflux from the cells. The increase in the inwardly directed protonmotive force (pmf) from this efflux induces dephosphorylation of the three phosphoproteins, as demonstrated by the effects of the protonophore CCCP and of artificially imposed transmembrane pH gradients. Upon darkening the cells, cessation of the proton efflux through bacteriorhodopsin causes a decrease in pmf, which induces rephosphorylation of the proteins. Pmf appears to function as a regulator rather than a driving force in this system. Measurements of pmf-driven ATP synthesis in our conditions indicate the regulation of protein phosphorylation by pmf is probably not a consequence of proton flux through the H+ ATPase, a known energy coupling structure in these cells. The properties of this system may indicate the existence of a pmf detector which regulates kinase or phosphatase activity; i.e., a regulatory coupling device.

scholarly journals Stochastic rotational catalysis of proton pumping F-ATPase

2008 ◽  
Vol 363 (1500) ◽  
pp. 2135-2142 ◽  
Author(s):  
Mayumi Nakanishi-Matsui ◽  
Masamitsu Futai
Keyword(s):  
Proton Transport ◽  
Atp Synthesis ◽  
Energy Coupling ◽  
Proton Pumping ◽  
Proton Channel ◽  
Phosphate Binding ◽  
Stochastic Fluctuation ◽  
Rotational Catalysis ◽  
Α Helix

F-ATPases synthesize ATP from ADP and phosphate coupled with an electrochemical proton gradient in bacterial or mitochondrial membranes and can hydrolyse ATP to form the gradient. F-ATPases consist of a catalytic F 1 and proton channel F 0 formed from the α 3 β 3 γδϵ and ab 2 c 10 subunit complexes, respectively. The rotation of γϵ c 10 couples catalyses and proton transport. Consistent with the threefold symmetry of the α 3 β 3 catalytic hexamer, 120° stepped revolution has been observed, each step being divided into two substeps. The ATP-dependent revolution exhibited stochastic fluctuation and was driven by conformation transmission of the β subunit (phosphate-binding P-loop/α-helix B/loop/β-sheet4). Recent results regarding mechanically driven ATP synthesis finally proved the role of rotation in energy coupling.

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